With less than a year before the release of "Ant-Man," Adam McKay has revealed that there were a number of rewrites to the upcoming comic book movie.

After Edgar Wright exited the film as director, McKay took over as the writer and he revealed that he and Paul Rudd, who will play the lead role, changed a number of parts from the script to make it bigger, more aggressive and a bit funnier. 

He told Collider, "The two of us holed up in hotel rooms on the east and west coast, and I think it was like six to eight weeks we just ground it out and did a giant rewrite of the script. ... We added some new action beats. I grew up on Marvel comics so the geek in me was in heaven that I got to add a giant action sequence to the movie; I was so excited. So we did, we added some cool new action. There's a lot that's already in there from what Edgar did, there's a lot of dialogue and character still in there."

McKay added that it was Rudd who called him up to take the writing job. He said "[Rudd] called me when Edgar Wright stepped away from the project and told me what was going on."

He continued, "I went and met with Marvel, and I was a little dubious just because I'm friends with Edgar and I didn't know what the story was, and then when I kind of heard what happened, that Edgar had parted ways, and then I saw their materials, I was like, 'God this is pretty cool.' Ultimately I didn't want to jump in as a director, I had too many other projects going and it was too tight, but I thought, 'You know what, I can rewrite this, and I can do a lot of good by rewriting it.'"

McKay also stated that after rewrites with Rudd, he hopes to do another script with the actor because it was an enjoyable experience. "We just shaped the whole thing, we just tried to streamline it, make it cleaner, make it a little bigger, a little more aggressive, make it funnier in places -- we just basically did a rewrite. Edgar had a really good script. But we just had a blast, and Rudd was just so much fun to write with. I walked away saying, 'Hey, you and I gotta write a script together.'"

"Ant-Man" is one of the most anticipated films of next year and one that Marvel hopes will be a huge box office success. The film will tell the story of Scott Lang, who must embrace his inner hero and help his mentor, Dr. Hank Pym, plan and pull off a heist that will save the world.

The film also stars Michael Douglas, Michael Pena, Bobby Cannavale, John Slattery, Evangeline Lilly, Judy Greer and Corey Stoll. Peyton Reed directed the film and Disney is set to release the flick on July 15, 2015.